Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752661AbaAPL5T (ORCPT ); Thu, 16 Jan 2014 06:57:19 -0500 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:35132 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751768AbaAPL5Q (ORCPT ); Thu, 16 Jan 2014 06:57:16 -0500 Date: Thu, 16 Jan 2014 11:56:34 +0000 From: Will Deacon To: Jean Pihet Cc: "linux-kernel@vger.kernel.org" , "linaro-kernel@lists.linaro.org" , "linux-arm-kernel@lists.infradead.org" , Arnaldo , "patches@linaro.org" , Jiri Olsa , Ingo Molnar Subject: Re: [PATCH] ARM64: perf: support dwarf unwinding in compat mode Message-ID: <20140116115634.GE30257@mudshark.cambridge.arm.com> References: <1389869123-5884-1-git-send-email-jean.pihet@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1389869123-5884-1-git-send-email-jean.pihet@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jean, On Thu, Jan 16, 2014 at 10:45:23AM +0000, Jean Pihet wrote: > Add support for unwinding using the dwarf information in compat > mode. Using the correct user stack pointer allows perf to record > the frames correctly in the native and compat modes. > > Note that although the dwarf frame unwinding works ok using > libunwind in native mode (on ARMv7 & ARMv8), some changes are > required to the libunwind code for the compat mode. Those changes > are posted separately on the libunwind mailing list. > > Tested on ARMv8 platform with v8 and compat v7 binaries, the latter > are statically built. I guess it makes sense to include this with your earlier series adding support for compat backtracing? > Signed-off-by: Jean Pihet > --- > arch/arm64/include/asm/ptrace.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h > index fbb0020..86d5b54 100644 > --- a/arch/arm64/include/asm/ptrace.h > +++ b/arch/arm64/include/asm/ptrace.h > @@ -133,7 +133,7 @@ struct pt_regs { > (!((regs)->pstate & PSR_F_BIT)) > > #define user_stack_pointer(regs) \ > - ((regs)->sp) > + (!compat_user_mode(regs)) ? ((regs)->sp) : ((regs)->compat_sp) In your previous series, compat backtracing is actually split out into a separate function (compat_user_backtrace), so it would be more consistent to have a compat_user_stack_pointer macro, rather than add this check here. Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/